Polymerization of acetylene



Patented Apr. 13, 1943 S] PATENT.

. POLYMERIZATION OF ACETYLENE Otto Fuchs, Frankfort-on-the-Main-Hochst,

Germany; vested in the Alien Property Custodlan , No Drawing. Application April 4, 1941, Serial No.

' 386,850. in Germany February 9, 1940 4 Claims; (omen-.678)

The present invention relates to the polymerization of acetylene.

Various'processes are already known for preparing aliphatic polymeric products of acetylene while using'a contact which consists of an aqueous or non-aqueous solution of cuprous salts and amino salts or alkali metal salts. Processes and catalysts for the production of non-benzenoid polymeric products of acetylene have been described in.U. S. Patents Nos. 1,811,959, 1,876,857, 1,926,039, 1,926,055, 1,926,056, 2,048,838, 2,110,971, 2,162,373 and elsewhere. All of this prior art is based upon the catalytic action of cuprous copper either alone or assisted by'another material as a catalyst. In said processes it may be suitable to choose thecuprous salts in as high a concentration as possible'in order to obtain a high yield within a certain'tiine and space.-

Since salt solutions of such a high concentration very readily tend to crystallization, it is necessary products separate automatically from the acetylene by cooling to -75 C.

in the industrial realization of the process to keep the concentration of the cuprous salt at a lower degree, whereby, however, the yield within a certain time and space is likewise correspondingly reduced.

' Now I have found that the concentration of the cuprous salt (and in consequence thereof the yield within a'certain time and space) may be increased, withoutthere existing any tendency of crystallization, by adding to the contact solution a substance capable of forming dipolar ions (Zwitterions) in the solvent used. As substances of the afore-named kind there may be used particularly amino-carboxylic acids, such as amino-acetic acid, alanine, amino-butyric and butadienyl-acetylene (cam) and a mixture of Cilia-polymers are removed from the contact solution by the current oi gas of the non-trans- .i'ormed acetylene leaving the chamber; these i It may be suitable to perform the reaction in an acidmedium; for this purpose a mineral acid, preferably hydrogen chloride, is added.

Besides water there are suitable as liquid medium for the, contact alcohols, for instance methyl-alcohol, ethyl-alcohol OIY'amYI-aICOIlQI.

The following examples serve to illustrate the invention, but they are not intended to limit it temperature amounts to 65 C.6'7 C. and the circulating portion of acetylene to 400 liters per.

hour. 45 grams of acetylene polymers are obtained per hour and per 2 liters of contact solu- V tion by means of a condensation at -75 C. 78.5 'per cent by weight of the acetylene polymers constitute C4H4 and 21.5 per cent are higher polymeric products (chiefly Celia-polymers).

(1b) Under the same conditions as those named in Example In, however at a circulating current of acetylene of 600 liters per hour there are obtained the corresponding figures: 39 grams 'of acetylene-polymers per hour and per 2 liters of contact solution; 85 per cent thereofare C4H4 and 15 per cent are CeHc and CaHa.

(2a) The contact solution consists of- 1700 grams CuaClz, 660 grams of NH4C1, 450 grams -of amino-acetic acid, 500 cc. of concentrated HCl and'lOO cc. of water; though this solution contains 54.5 per cent of CuzCli more than the solution of Example 10, its saturation temperature (32 C.) is even 1 degree lower. Under the experimental conditions named in Example 1a there are thus obtained: grams of acetylene polymers per hour and per 2 liters of contact solution; 73 percent thereof are C4114 and 27'- per cent are CcHe and CaHa.

(2b) By using the Same contact solution as in Example 2a, increasing, however, the circulating portion of acetylene to 600 liters per hour I and per 2 liters of contact solution is considerably increased by raising the concentration of the OFFICE cuprous chloride; this increase has been renderedpossibleby the addition oi-amlno-acetic acid and when the same portion of acetylene is caused to circulate this increase is greater in the polymers CsHs and CsHa than in the polymeric product C4H4 (see Examples in and 20); but if it is desired to obtain C4H as the main product this increase of the yield within a certain time and space may be displaced in favor of 04114 by an increased circulation of acetylene (see Examples 1a and 2b). t

Gram of This crude roduct the crude contains 0 an Alain Oircuproduct CaH: P y Example acetic lat-mg per hour acid portion of and per 2 0,11, liters 0i Per cent contact Grams Y solution weight la Without 400 liters 45 9. 7 21. 5

per hour. 20 With 400 .liters 65 7- 5 27 per hour. l b Without 600 liters 39 '5. 8 5

l per hour. 2b With.. 600 liters 57' 10.5 8- 5 per hour.

I claim:

1. In the process of polymerizing acetylene to non-benzenold polymers thereof the step which comprises passing acetylene through a catalyst containing a liquid medium, a cuprous salt, a salt of the group consisting of alkali metal salts consisting of aminocarboxylic acids,

and ammonium salts and an organic compound capable of forming dipolar ions in, said liquid medium and selected from the class consisting of aminocarboxylic acids. betaines, peptides and polypeptides. a 2. In the process of-polymerizing acetylene to non-benzenoid polymers thereof the step which comprises passing acetylene through an aqueous catalyst, containing a cuprous salt, a salt of the group consisting of alkali metal salts and ammonium salts, a mineral acid and an organic compound capable of forming dipolar ions in aqueous solution and selected from the class betaines,

peptides and polypeptides. v

3. In the process of polymerizing acetylene to non-benzenoid polymers-thereof the step which comprises passing acetylene through an aqueous catalyst, containing a cuprous salt, a salt of the group consisting of alkali metal salts and ammonium salts, a mineral acid and an aminocarboxylieacid capable of forming dipolar ions in I aqueous solution.

4. In the process of polymerizing acetylene to non benzerioid polymers thereof the step which comprises passing acetylene through an aqueous catalyst containing cuprous-chloride, ammonium chloride, hydrogen chloride and amino-acetic ,acid. 

